The IJ took the 76, 47 hex but I moved back in opening the hex sides on both the NE and SW side of the hex, which he then recaptured completely, owning all hex sides. Then I moved through again before he could move into 76, 46 with his units ( I already had a unit started which only required one day to move and he did not/could not have had the same as he had just taken the hex the day before). So I should own that hex side again but instead it's blue and I at least can't use it at all.
So the order is as follows:
1. He took the hex.
2. My units moved in one day later from both sides on the road as they had already started and thus got hex side control again along the road.
3. He took the hex again.
4. I had another unit moving (from 76, 46, so through the blue line area) which did move and should have gained the hex side control again. Instead the blue line appeared. Units moving from the other side got hex side control a day later (as shown in the map with green on both sides).
5. I tried to move another unit through literally the next turn, but it would not go that way, and instead rerouted to an adjacent hex if sent. That's when I checked with the 'W' key and saw this blue line.
A save follows.






